Pressure cookers and the like



' 7, 1956 w. FRITSCH 2,757,685 PRESSURE COOKERS AND THE LIKE I Original Filed May 20. 1952 flwezzfari WILL-Y FK/TScH 2,757,685 nnssnnn coorrnns nn THE ruin Willy Fritseh, ll lettmann, Rhinelaud, Germany Original application May. 2d, 1952, Serialhlo, 28%,961. Divided and this application ()ctbber 27, 1953, Serial N usea t Claims priority, application Germany May 21,1951,

" "8 Claims. (Cl. 137 525) Thepresent invention relates to pressure cookers and the like; I

More particularly, the present invention relates to the combination of a means for visually indicating the pressure within a pressure cooker and the like with a-safety. means for limiting the pressure within apres'sure cooker or the like and for giving a visual'and aural indication that the upper limit of pressure within the cooker or the like has been reached. 1

The present application is a division of co-pending application Serial N0.'288,90l, filed May 20, 1952,: anden-- titled Pressure Cooker. 4 One of the objects of the present invcntionis to-provide an exceedinglylsimple means for visually indicating the pressureswithina pressure cooker or the like. .Another object of the present invention is to provide a best'understoodfrom' the following-description of specific" embodimentswhen read in connectionwith thewaccom-f' visual pressure indicating means capable of being-easily adapted to operate through different pressure ranges.

s A further object of the present invention is to provide an exceedingly simple safety release for releasing the pressure in apressure cooker orv the like Whenthis pressure reaches a predetermined limit.

An additional object of the present invention is .to

provide a safety means which will not become stopped up during operation. v a

Still anotherobject of the present invention is to provide such a safety release with a resilient means which is capable of maintaining its resiliency for a long period of .7 With the above objects in view, the present invention.

mainly consists of a pressure cooker provided at its coveror at some other suitable location with a top wall portion and a side wall portion extending downwardly from theperiphery of the top wall portion, these wall portions having an outer surface adapted to form part of the outside and an inner surface adapted to define part of the innerspace of apressure cookeror the like, and these top and sidewall portions respectively being formed with a top opening and a side opening. A rod extends freely through the top opening and has spaced parts respectively located on. opposite sides of the top wall portion,'and a pairof members are respectively fixed to the spaced parts of therod. and are larger than the top opening to limit movement of the rod in oppositedirection through the top opening, these members and rod having a predetermined weight urging one of the members against the outer surface ofthe top wall portionover the top opening when the pressure in the pressure cooker is not substantially above atmospheric pressure andthe other of these members being adapted to be acted on by pressure in the cooker or the like, to raisethernembers and rod so that the distance of the s'aid one member above the top Wall portion gives a visual indi cat ion of the-pressure within thecooker orthe to pro-,

'conicalstop wallportion'." w s r Patented Aug. 7, i;

like. A resilient means engages theouter surface of the sure within the cooker or the like and to provide anup er limit to'th'e force acting on the rod and'the' members con-' nectedthereto;

J The novelfeatures which are considered as character istic forthe inventionareset forth-in particular in the appended claims The inventionitself, however, both as" toits' construction and its method of operation-,"together with. additional objects and advantages thereo-f, will be* Referring now to-the drawings, it will be seen that the pressure cooker-cover 3'is: provided in its central portion with a hollowdome-shaped knob '4 which is provided with the apparatus'of the invention; As is apparenhfroi'n' Fig. l,--.thisahollow dome-shaped knob s is provided 'witha substantially cyiindrical side wall portion extending downwardly from the periphery of a The side wall portion is'formed in its outer face with anannular groove Saudis furtherformed with' a pin A resilient ring 7 made of rubber or the like is located about the outer surface of the side wall portion-and-forms a-resilient -meanscovering 1 the side openings 6 to form a safety release as described; below. The resilient rubberring 7 is of a .circulancrosssection having a diameter" substantially larger than the width of the annular groove 5 so that the ring 7 bears against the opposite side edges" 9 of the groove SWllh predetermined force and'is spaced-from all parts-of groove 5 except'the opposite side edges 91 thereof so as 'to provide an annular space between the ring 7 and openings 6. A steel coilspring 8 is: embeddedtwithin the ring '7, during molding of thelatter,, so-that-:the resiliency of 'the'ring 7 isrnaintain'ed in'full force over-a long periodof time, audit will be seen that no part of the members '7 and '8' are subject to-corrosion or other deleterious phenomena. Further more, there are no'diilicultie's with respect to maintaining" the spring 8-in' its position with respect to ring 7 because this spring 8 is embedded within the ring '7. The ring 7 presses witha predetermined resilient'force against the side edges 9 of'groove 5 so that when thepressure within the-cooker exceeds this predetermined force'the pressure will move the ring "1' at least partly away from "one of the edges 9, so that the ring '7 cooperates with the openings 6 to provide a safety release, whereas while thepressure within the cooker is below that with which the ring 7 bearsagainst the edges 9 the interior'of'the cooker is effectively sealed by the ring'7. Furthermore,

pressure cooker circular :and slightly tion of the safety release is automatically assured. Also, when the steam escapes between ring 7 and a part of an edge 9, a whistling sound is produced to provide an aural indication that the upper pressure has been reached, and also the escaping steam gives a visual indication that the upper pressure limit has been reached.

The structure for indicating the pressure within the pressure cooker includes the opening 11 formed in the top wall portion of the hollow knob 4, and a rod 10 extending freely through this opening 11 and having spaced parts located respectively on opposite sides of the top wall 4. A pair of members 12 and 13 are respectively fixed to these spaced parts of the rod 10, the upper member 12 as well as the lower member 13 beinglarger.

than the-opening 11 and the upper member 12 serving as-an indicating member. Thus, the weight of members 10, 12 and 13 urges the upper member 12 over the opening 11 into engagement with the outer surface of knob 4, as'shown in Fig. 1, when the pressure within the cooker is not substantially above atmospheric pressure, whereas the pressure within the cooker acts on the relatively large bottom face of member 13 to raise the latter together with members 10 and 12 as the pressure within the cooker increases so that the distance of member 12 above the top surface of the pressure cooker gives a visual indication of the pressure within the cooker. If desired, suitable gradations may be provided along the rod 10 between members 12 and 13 to cooperate with the top rim of opening 11 to indicate the extent to which member 12 has moved up. A sealing ring 14 is located about the rod 10 next to the top surface of member 13 and seals the opening 11 when the membcr 13 is located closely adjacent to opening 11.

The member 13 is removably connected to the rod 10, as by being screwed thereto, so that similar members 13 of different weights may be connected to the rod 10 and in thisway it is an exceedingly simple matter to adjust the apparatus to be used at high pressures or at relatively low pressures. Of course, when changing the member 13, it is also necessary to change the ring 7 for a ring having a correspondingly greater or smaller force, because there is a close cooperation between the pressure indicating structure and the safety release structure. For example, if the structure is designed to cause sealing ring'14- to close opening 11 when the pressure within the cooker is one corresponding to a temperature of 102 C., then'the force of ring 7 is such that it will be separated from part of an edge 9 when-the pressure within the cooker is one which corresponds to a temperature of 105-107 C., for example, so that the safety release apparatus will prevent the pressure within the cooker from building up excessively to avoid serious accidents. With a structure having these characteristics, the cooker will operate to cook food at a temperature of between 102 and 105 C. It is evident, however, that by proper choice of ring 7 and weight 13 the apparatus may operate within any desired range the only requirement being that the force of ring 7 against the edges 9'must always be slightly greater than the force required to raise the sealing ring 14 into sealing relationship with the opening 11.

It will be understood that each of the elements described above, or two or more together, may also find auseful application in other types of pressure cookers differing from the types described above.

While the invention has been illustrated and described as embodied in pressure indicating and safety release apparatus for pressure cookers and the like, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departting in any way fromthe spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the stand point of prior art, fairly constitute essential. characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. For use in a pressure cooker or the like, in combination, a top wall portion and a side wall portion extending downwardly from the periphery of said top wall portion, said wall portions having an outer surface adapted to form part of the outside and an inner surface adapted to define part of the inner space of a pressure cooker or the like, said top and side wall portions respectively being formed with a top opening and a side opening; a rod extending freely through said top opening and having spaced parts respectively located on opposite sides of said top wall portion; a pair of members respectively fixed to said spaced parts of said rod and being larger than said top opening to limit movement of said rod in opposite directions through said top opening, said members and rod having a predetermined weight urging one of said members against the outer surface of said top wall portion over said top opening when the pressure in the pressure cooker is not substantially above atmospheric pressure and the other of said members being adapted to be acted on by pressure in the cooker or the like to raise said members and rod so that the distance of said one member above said top wall portion gives a'visual indication of the pressure within the cooker or the like; and resilient means engaging said outer surface of said side wall portion with a predetermined pressure and covering said side opening so that when the pressure in the cooker or the like exceeds said predetermined pres sure said resilient means moves at least partly away from said outer surface of said side wall portion to provide an escape to the atmosphere, so that said resilient means cooperates with said side opening to provide a safety release for the pressure within the cooker or the like and to provide an upper limit to the force acting on said rod and members connected thereto.

2. For use in a pressure cooker or the like, in combination, a top wall portion and a side wall portion extending downwardly from the periphery of said top wall portion, said wall portions having an outer surface adapted to form part of the outside and an inner surface adapted to define part of the inner space of a pressure cooker or the like, said top and side wall portions respectively being formed with a top opening and a side opening; a rod extending freely through said top opening and having spaced parts respectively located on opposite sides of said top wall portion; a pair of members respectively fixed to said spaced parts of said rod and being larger than said top opening to limit movement of said rod in opposite directions through said top opening, said members and rod having a predetermined weight urging one of said members against the outer surface of said top wall portion over said top opening when the pressure in the pressure cooker is not substantially above atmospheric pressure and the other of said members being adapted to be acted on by pressure in the cooker or the like to raise said members and rod so that the distance of said one member above said top wall portion gives a visual indication of the pressure within the cooker or the like, said other member being removably connected to said rod so as to be replaceable by similar members of different sizes and weights; and resilient means engaging said outer surface of said side wall portion with a predetermined pressure and covering said side opening so that when the pressure in the cooker or the like exceeds said predetermined pressure said resilient means moves at least partly away from said outer surface of said side wall portion to provide an escape to the atmosphere, so that said resilient means cooperates with said side opening to provide a safety release for the pressure within the cooker or the like and to provide an upper limit to the force acting on said rod and members connected thereto.

3. For use in a pressure cc aker or the like, in combination, a top wall portion and a side wall portion extending downwardly from the periphery of said top wall portion, said wall portions having an outer surface adapted to form part of the outside and an inner surface adapted to define part of the inner space of a pressure cooker or the like, said top and side wall portions respectively being formed with a top opening and a side opening; a rod ex tending freely through said top opening and having spaced parts respectively located on opposite sides of said top wall portion; a pair of members respectively fixed to said spaced parts of said rod and being larger than said top opening to limit movement of said rod in opposite directions through said top opening, said members and rod' having a predetermined weight urging one of said members against the outer surface of said top wall portion over said top opening when the pressure in the pressure cooker is not substantially above atmospheric pressure and the other of said members being adapted to be acted on by pressure in the cooker or the like toraise said members and rod so that the distance of said one member above said top wall portion gives a visual indication of the pressure within the cooker or the like, said other member having a top face directed toward said inner surface of said top wall portion; a sealing ring located about said rod adjacent to said top face of said other member to seal said top opening when said other member becomes located closely adjacent thereto; and resilient means engaging said outer surface of said side wall portion with a predetermined pressure and covering said side opening so that when the pressure in the cooker or the like exceeds said predetermined pressure said resilient means moves at least partly away from said outer surface of said side wall portion to provide an escape to the atmosphere, so that said resilient means cooperates with said side opening to provide a safety release for the pressure within the cooker or the like and to provide an upper limit to the force acting on said rod and members connected thereto.

4. For use in a pressure cooker or the like in, combination, a top wall portion and a side wall portion extending downwardly from the periphery of said top wall portion, said wall portions having an outer surface adapted to form part of the outsidev and an inner surface adapted to define part of the inner space of a pressure cooker or the like, said top and side wall portions respectively being formed with a top opening and a side opening; a rod extending freely through said top opening and having spaced parts respectively located on opposite sides of said top wall portion; a pair of members respectively fixed to said spaced parts of said rod and being larger than said top opening to limit movement of said rod in opposite directions through said top opening, said members and rod having a predetermined weight urging one of said members against the outer surface of said top wall portion over said top opening when the pressure in the pressure cooker is not substantially above atmospheric pressure and the other of said members being adapted to be acted on by pressure in the cooker or the like to raise said members and rod so that the distance of said one member above said top wall portion gives a visual indication of the pressure within the cooker or the like; and a resilient ring engaging and extending about said outer surface of said side wall portion with a predetermined I pressure and covering said side opening so that when the pressure in the cooker or the like exceeds said predetermined pressure said ring moves at least partly away from said outer surface of said side wall portion to provide an escape to the atmosphere, so that said ring cooperates with said side opening to provide a safety release for the pressure within the cooker or the like and to provide an upper limit to the force acting onsaid rod and members connected thereto.

5. For use in a pressure cooker or the like, in combination, a top wall portion having a circular periphery and a cylindrical side wall portion extending downwardly from the periphery of said top wall portion, said wall portions having an outer surface adapted to form part of the outside and an inner surface adapted to define part of the inner space of a pressure cooker or the like, said top wall portion being formed with a top opening and said side wall portion being formed in its outer surface with an annular groove and with a plurality of annularly spaced side openings distributed about said annular groove and located within the confines thereof; a rod extending through said top opening and having spaced parts respectively located 011 opposite sides of said top wall portion; a pair of members respectively fixed to said spaced parts of said rod and being larger than said top opening to limit movement of said rod in opposite directions through said top opening, said members and rod having a predetermined weight urging one of said members against the outer surface of said top wall portion over said top opening when the pressure in the pressure cooker is not substantially above atmospheric pressure and the other of said members being adapted to be acted on by pressure in the cooker or the like to raise said members and rod so that the distance of said one member above said top wall portion gives a visual indication of the pressure within the cooker or the like; and a resilient rubber ring having a circular cross section of a diameter substantially larger than the width of said annular groove located about the latter and engaging said outer surface of said side wall por tion at opposite side edges of said groove with a predetermined pressure to form in said groove an annular space between said side openings and ring so that when the pressure in the cooker or the like exceeds said predetermined pressure said ring moves at least partly away from at least one of said side edges of said groove to provide an escape to the atmosphere, so that said ring cooperates with said groove and side openings to provide a. safety release for the pressure within the cooker or the like and to provide an upper limit to the force acting on said rod and members connected thereto.

6. For use in a pressure cooker or the like, in combination, a top wall portionhaving a circular periphery and a cylndrical side wall portion extending downwardly from the periphery of said top wall portion, said Wall portions having an outer surface adapted to form part of the outside and an inner surface adapted to define part of the inner space of a pressure cooker or the like, said top Wall portion being formed with a top opening and said side wall portion being formed in its outer surface with an annular groove and with a plurality of annularly spaced side openings distributed about said annular groove and located within the confines thereof; arod extending through said top opening and having spaced parts respectively located on opposite sides of said top wall portion; a pair of members respectively fixed to said spaced parts of said rod and being larger than said top opening to limit movement of said rod in opposite directions through said top opening, said members and rod having a predetermined weight urging one of said members against the outer surface of said top wall portion over said top opening when the pressurev in the pressure cooker is not substantially above atmospheric pressure and the other of said members being adapted to be acted on by pressure in the cooker or the like to raise said members and rod so that the distance of said one member above said top wall portion gives a visual indication of the pressure within the cooker or the like; a resilient rubber ring having a circular cross section of a diameter substantially larger than the width of said annular groove located about the latter and engaging said outer surface of said side wall portion at opposite side edges of said groove with a predetermined pressure to form in said groove an annular space between said side openings and ring so that when the pressure in J7 th ,999 95 !thslike mseds a p e t rmi e p e su said ring moves at least partly away from at least one of said side edges of said groove to provide an escape to the atmosphere, so that said ring coopdrates with said grooveand side openings to provide a s "ety release for the pressure within the cooker or the like and to provide an upper limit to the force acting on stiid rod and members connected thereto; and an annular metallic coil spring embedded'in said rtibberringl 7. For use in a pressure cooker or the like, in'combination, ,a cover'having atop. wall portion and a side wall portion'extending downwardlv'from the'periphery of said top wall portion, said wall portions havingan outer surface adapted to form part of the outside and an inner surface adapted to define part of the inner space of a pressure cookeror the like, said top and side wall portions respectively being formed with a top. opening and a side opening; a rod extending freely through said top opening and having spaced parts respectively located on opposite sides of said topwall portion; apair of mernhers respectively fixed to said spaced parts of said'rod and being largerthan saicLtop openingto limit movement of said rod in opposite directiensthrough said top opening, said members and rod having a predetermined weight urging onept said members @ainst the outer surface of said top wall portion over said top openingiwhen the pressure in the pressure cooker is not substantially above atmospheric pressure and the other of said members being adapted to be ,acted on by pressure in the eookeror the like to raise said members and rod so that the distance of said one member above said top wall portion gives a visual indication of the pressure within the cooker or the like; and resilient means engaging said outersurface of said side wall portion with a predetermined pressureand covering said side opening 50 that when the pressure in the'cooker or the like exceeds said predetermined pressure said resilient means moves at'least partly away from said'outer surface of said side Wall portionto providean escape tothe atmosphere, so that said resilient means cooperates with said side opening to provide a safety release for the pressure within the cooker or the like and to provide an upperv limit to the .force acting on said rod and members connected thereto.

8. For use in a pressure cooker or the like, in com.- bination, a cover having a dome-shaped knob provided with a top wall portion. and a side wall portion extending downwardly from the periphery of said top wall portion, said wall portions having an outer surface adapted to form part of the outside and an inner surface adapted to define part of the inner space of a pressure cooker or the like, said top and side wall portions respectively being formed With a top opening and a side opening; a rod extending freely through said top opening and having spaced parts respectively located on opposite sides of said top wall portion; a pair of members respectively fixed to said spaced parts of said rod and being larger than said top opening to-lirnit'movement of said rod in opposite directions through said top opening, said members and rod having a predetermined weight urging one of said members against the outer surface of said top wall portion over said top opening when the pressure in the pressure cooker is not substantially above atmospheric pressure *andthe other of'said members being adaptedto he actedonhy pres'darein the cooker or the like to' raise said'rnembers androdiso that the distance of saidone member above said top wallportion gives a visual indication of the pressure within the cooker or the like; and resilient-means engaging'saidouter surface of said side wall-portion with apredetermined pressure and covering said side'opening so that'when the pressure in the cooker or the like-exceeds said predetermined pressure said resilientmeans moves at least partlyaway from said outer surfa'ee ofisaids-ide w-allportion to provide an escape to the atmosphere, so that said resilient means cooperates withusaid side opening to provide a safety release for the pressure within the cooker or thelike and to provide an upper-limit to the force acting on'said rodand members connected thretoa 1 l References Cited in the file of this patent 'jUNlTE'D STAT ES PATENTS Kroupa Feb. 22, 1921 D avis Mar. 15, 1921 S tates July 9, 1 946 FOREIGN PATENTS 28,455 Norway Dec. 21, 1917 650,769 Germany Sept. 30, 1937 Germany Aug. 27, 

